Now the conventions are over the US Presidential election is really heating up.

Mitt Romney is now regularly using his Twitter account to attack President Obama while the president is taking a more positive tone and continues to win the social media numbers game.

The attacks by Romney helped it part to ensure that the number of mentions he picked up (both positive and negative) soared this week.

He has recently posted tweets such as:

.@barackobama has failed to stop China and has failed American workers. It’s time to stand up to China mi.tt/U9mlW6

— Mitt Romney (@MittRomney) September 13, 2012

And:

With @barackobama’s defense cuts threatening jobs & putting families at risk, folks in Virginia are not better off mi.tt/OgseDU

— Mitt Romney (@MittRomney) September 7, 2012

In fact, most of the posts seem to be a direct attack on the President. By contrast, President Obama’s tweets cite celebrities:

Beyoncé and Jay-Z are hosting the President in New York—your chance for two spots on the guest list ends at midnight: OFA.BO/X4goCa

— Barack Obama (@BarackObama) September 14, 2012

In general, the tone the Obama’s tweets are more positive than his Repbulican challenger. The only real personal and attacking comments revolve around Mitt Romney’s tax returns, an issue the campaign is keen to keep live:

RT if you agree: Romney should come clean and release his tax returns so voters know whether he paid his fair share.

— Barack Obama (@BarackObama) September 13, 2012

The President is still winning the social media numbers race. He is approaching 20 million followers on Twitter, while the Republican challenger is on just over 1 million.

You can see from this week’s Washington Post @mentionmachine that Romney’s name popped up more than 150,000 times more than Obama’s.

On Facebook, the President is winning 28 million to 6 million. Romney’s team do seem to be making better use of video than the President,  with his team frequently linking to ads and videos on YouTube.

Despite launching the account with a fair bit of fanfare, Barack Obama has only checked in once on Foursquare. As the ground war heats up, the Obama team should look to increase this to engage with supporters in locations across the country.

On Facebook Insights, only Romney is the only candidate who is increasing the number of conversations around them in the last three days. This may partly be down to his controversial remarks after the death of the US Ambassador in Libya, which many in the US disagreed. It also emphasises yet again that it is still offline stories that drive online conversations when it comes to politics.